A study of bound states of $\eta, \eta^{'}, D^{0}$, $\bar{D^{0}}$, $B^{0}$, $\bar{B^{0}}$, $\bar{K^{0}}$ and $\phi$ mesons with light and heavy nuclei within chiral SU(3) model

TL;DR

This study investigates the formation of bound states of various mesons with nuclei using a chiral SU(3) model, revealing significant mass shifts and potential bound states for certain mesons in heavy nuclei.

Contribution

It applies the chiral SU(3) hadronic mean field model to predict meson-nucleus bound states, including mass shifts and decay widths, for a range of mesons and nuclei, which is a novel comprehensive analysis.

Findings

Significant negative mass shifts for $ ext{eta}$, $D^0$, $ar{D}^0$, $B^0$, $ar{B}^0$, and $ar{K}^0$ mesons at nuclear saturation density.

Bound states are likely for these mesons in heavy nuclei, especially for ground and some excited states.

Small mass shifts for $ ext{eta}^{' }$ and $ ext{phi}$ mesons, with no bound states formed.

Abstract

In the present work we explore the possibilities of the formation of bound states of neutral pseudoscalar mesons $\eta, \eta^{'}, D^{0}$, $\bar{D^{0}}, B^{0}, \bar{B^{0}}$ and $\bar{K^{0}}$ and the vector meson $\phi$, with the nuclei $^{12}$C, $^{16}$O, $^{40}$Ca and $^{208}$Pb, calculating their binding energy and absorption decay width. To calculate the optical potentials of these mesons in different nuclei under study, we shall use the chiral SU(3) hadronic mean field model, in which the properties of nucleons in the medium are modified through the scalar isoscalar fields $\sigma$ and $\zeta$ and the scalar-isovector field $\delta$. The scalar-isovector field $\delta$ account for the finite isospin asymmetry of different nuclei having asymmetry in number of protons and neutrons. The binding energy and absorption decay width of mesons are calculated for the ground state and some of possible excited states of the nuclei. In the chiral SU(3) model, the mesons $ \eta, D^{0}$, $\bar{D^{0}}, B^{0}, \bar{B^{0}}$ and $\bar{K^{0}}$ are observed to have significant negative mass shift upto nuclear saturation density which lead to the possibility of the bound states at least for ground states and some of excited states in case of heavy nuclei. For the pseudoscalar singlet $\eta^{'}$ and the vector meson $\phi$ the mass shift obtained are found to be small and bound states are not formed. The present calculations are compared with different studies available in the field and will be useful in understanding the outcomes from different experimental facilities focusing on this area of research.